query method
Implementation
Future<QueryResult> query(String sql,
[List<Object?> parameters = const []]) async {
final result = await _request('query', [sql, parameters]) as List;
return QueryResult(
List<String>.from(result[0] as List),
(result[1] as List)
.map((row) => List<Object?>.from(row as List))
.toList());
}